The subject matter disclosed herein relates to a surgical navigation system operable to track an ultrasound catheter.
Surgical navigation systems implementing electro magnetic (EM) technology can track the position and/or orientation of a medical instrument and convey this location to a user. The position and orientation information can be conveyed by virtually superimposing a graphic representation of the distal end of the medical device onto a patient image. Accordingly, the user receives visual feedback to help navigate or guide the medical device to a target site.
Conventional surgical navigation systems generally include a tracking element disposed near the proximal end of the tracked instrument such that the tracking element does not interfere with the performance of the medical procedure. The tracking element may comprise a magnetic field generator or a magnetic field sensor, and may comprise one or more coils defining a variety of different coil configurations. As medical personnel are frequently more concerned with the position and orientation of the distal end of the medical instrument, it is often necessary to estimate the distance between a tracking element disposed near the proximal end of an instrument and the instrument's distal tip. One problem associated with tracking a catheter-based medical instrument is that catheters are flexible which may cause the distance between the proximal end and the distal end to vary. Another problem associated with tracking an ultrasound catheter device is related to interference from the ultrasound motor that can render any tracking system position and orientation estimates less precise.